FIG. 5.

(a) Schematic illustration of the breakdown of the total set of 3-3-2 functions by closed sets (closed under variable permutation), MI classes, and Delta classes and the correspondence between the MI and Delta classes. The set of all (512) functions (represented by column I in blue) is partitioned into 18 sets closed under the permutation of variable values (represented by column II in purple). The closed sets are then grouped into either 16 MI classes or 17 Delta classes represented by columns III and IV correspondingly. The sizes of the multicolored segments in columns III and IV show how many closed sets the corresponding classes contain. The colors of the segments are defined in panel (b). The order of closed sets being grouped is the same between MI and Delta classes, so columns III and IV illustrate how the MI and Delta classes correspond to one another: 15 classes are identical between MI and Delta landscapes, and 1 MI class is split into 2 Delta classes (as pointed out in column VI). Column V also shows how many functions are contained in different groups of classes. (b) Color scheme of the classes by the number of closed sets contained in them and the corresponding number of MI and Delta classes.